We were honored by your interest in our article entitled "Early Markers of Atherosclerotic Disease in Individuals with Excess Weight and Dyslipidemia" published in Arquivos Brasileiros de Cardiologia.

The finding of high fibrinogen levels in patients with atherosclerotic disease has generated a large volume of clinical evidences in the past few decades, and has been considered a risk marker for cardiovascular events. High fibrinogen levels are also known to promote atherosclerotic disease by increasing blood viscosity, stimulating fibrin formation and increasing platelet aggregation. In the setting of an inflammatory status such as that seen in individuals with excess weight, the higher hepatic production of fibrinogen regulated by inflammatory cytokines may be an important link in the progression of the atherosclerotic disease in its different subclinical and clinical stages. Our study had a small sample size, however large enough to bring this association to light.1

As regards the assessment of serum levels of vitamin B12 and vitamin D, in a recent study with a small sample, Baser et al2 observed the association of vitamin D deficiency with high fibrinogen levels and pro-oxidative serum markers. Vitamin B12 deficiency, by hyperhomocysteinemia induction, also plays a role in the development of cardiovascular disease. Every 5-mcmol/L increase above 10 mcmol/L in serum levels of homocystein is associated with a 20% increase in the risks of circulatory disorders.3

Although the assessment of changes in endothelial function in patients with vitamin B12 and vitamin D deficiency had not been included in this study, it is a promising research field. In a study with a small sample assessing endothelial function using flow-mediated brachial artery dilatation in patients with vitamin B12 deficiency, increased dilatation after proper vitamin B12 replacement was observed.4 A similar finding was observed in a sample of individuals undergoing hemodialysis after vitamin D replacement.5

We thank Dr. Cerit's remarks and are satisfied to stimulate discussion regarding this important field of clinical cardiology, which has been a frequent concern in daily practice, in view of the growing incidence of obesity among our society.

Eduardo Menti

Ao Editor,

Li, com grande interesse, o artigo intitulado "Marcadores Precoces de Doença Aterosclerótica em Indivíduos com Excesso de Peso e Dislipidemia", de Menti et al.,1 recentemente publicado nos Arquivos Brasileiros de Cardiologia 2016;106:457-63. Os investigadores relataram que o fibrinogênio está associado a aterosclerose subclínica em indivíduos com excesso de peso.

Vários estudos mostraram que níveis aumentados de fibrinogênio sérico estão fortemente associados a doença arterial coronariana.2^,3 Altos níveis de fibrinogênio podem contribuir para doenças vasculares através do aumento da viscosidade sanguínea, do estímulo à formação de fibrina, ou do aumento da interação plaqueta-plaqueta.2^,3

Catena et al.4 relataram que o nível de homocisteína plasmática (Hcy) estava diretamente correlacionado à idade, circunferência abdominal e aos níveis de glicemia de jejum, triglicérides, ácido úrico e fibrinogênio, e inversamente correlacionado ao clearance de creatinina e aos níveis de colesterol lipoproteína de alta densidade, vitamina B12 e folato. A baixa concentração de vitamin B12 e a hiperhomocisteinemia são comuns e podem afetar o nível de fibrinogênio sérico.

A deficiência de 25-hidroxivitamina D [25(OH)D] com risco aumentado de doença cardiovascular e tromboembolismo venoso pode estar associada a respostas hemostáticas e inflamatórias adversas. Blondon et al.5 relataram que baixos níveis de 25(OH)D sérica estavam transversalmente associados a altos níveis de interleucina-6, homocisteína, inibidor da via do fator tecidual e inibidor-1 do ativador do plasminogênio.

Em vista desses achados, pode ser útil avaliar os níveis séricos de vitamina B12, Hcy e [25(OH)D] devido à sua íntima associação com o nível de fibrinogênio.